[dosdan]

I want to ask a question to persons who have had multiple copies of lenses passing through their hands for a significant length of time, say 10 or more years. You would probably be a dealer or work in a camera store.

1. Have you noticed changes in the quality control in the different brands over the years?

2. Are modern "digital" lenses better than the older film lens (sentimentality aside), or did lens design & manufacturing technology plateau some time ago and modern lens are just juggling with the same trade-offs, just APS-C versions of film lenses or able to use cheaper materials more effectively to produce lighter/cheaper lenses?

photozone.de mentioned that about 15% of ALL lenses they test are rejected because of quality faults. Does that agree with your experience?

[Lowell Goudge]

I am neither a dealer or collector, but just a photographer.

I think there are really 2 issues here, image quality and build quality.

Many new lenses clearly have better image quality than older lenses, BUT having said that there are examples of excellent older lenses as well.

What I have noticed however, is that in order to get the cost down, many newer lenses feel cheap compared to older ones. this was especially true in the 1990's as plastics were introduced. This does not mean plastics are for cheap lenses, but it did generate that perception.

While there have been some recient issues with quality, I believe that is primairly due to shifting manufacturing sites. Many new lenses are in new factories in china. this is not meant to be a china bashing post, I am just simply pointing out that these factories do not have up to 100 years of know how instilled into them. Irrespective of design, worker experience can be a significant factor, in production quality.

Just as a reminder, you may remember that all Japaneese lenses used to have a little oval quality sticker, because at one point they were viewed as inferior and of poor production quality. Sounds a lot like the situation with china today, doesn't it.

[Jodokast96]

The biggest improvements can be seen in zoom lenses. Just look at something like the 18-250. Not only have you never seen a lens like that in the past, it would never have had the same IQ. In the past, the general belief was when you wanted the best quality glass, you used primes. That's not quite as true today. That gap has narrowed significantly.

[Shashinki]

I'm noticing that QC on Sigma lenses (and 3rd party lens manufacturers' lenses in general) is alot better now than it used to be only 4-5 years ago.

[dosdan]

My gut feeling is that the image quality of the top lenses of about 10-20 years ago probably can't be improved upon, but modern automation, new production techniques, improvements in materials and a bigger leisure products user base and hence bigger potential volume of production means that today's lenses (taken as a group) have a much better performance/price ratio than 10 years ago.

I'm not so sure about the percentage of rejects for the group as a whole. Better or worse than before?

[Marc Langille]

My gut feeling is that the image quality of the top lens of about 10-20 years ago probably can't be improved upon, but modern automation, new production techniques, improvements in materials and a bigger leisure products user base and hence bigger potential volume of production means that today's lens (taken as a group) have a much better performance/price ratio than 10 years ago.

The only exception are the super telephotos - still quite pricey, but newer units use lighter materials. Some of the Canon or Nikon lenses are magnesium bodies, so care around salt water environments need to be observed (IIRC).

Cheers,
Marc

[k100d]

The biggest improvements can be seen in zoom lenses. Just look at something like the 18-250. Not only have you never seen a lens like that in the past, it would never have had the same IQ. In the past, the general belief was when you wanted the best quality glass, you used primes. That's not quite as true today. That gap has narrowed significantly.

according to Adam-T, this 28-200 was great Vivitar 28-200 F3.5-5.3 Kiron/Kobori: Pentax SLR Talk Forum: Digital Photography Review